Electronic excitations in many-particle systems: a quantitative analysis

Small particles, produced in usual experiments, commonly form many-particle systems. Interactions of various kinds among the particles influence the properties of such systems. We consider here the optical properties of noble metal particle systems with separated nearly spherical particles and with aggregates formed by induced coagulation of the single particles. In order to describe their optical extinction we apply electrodynamic interaction models on particles and aggregates. We perform a quantitative analysis of the extinction spectrum of one selected sample with the electrodynamic interaction model.